Blender 2.80 Cycles light wont render
I don't see any problem in your file, except that the light sources are really dim. If you look closely in your screenshot, you can even see a faint reflection. Note that you have volumetric scattering on, which will make things dimmer than they would be otherwise.

Things you can try:


Increase the emission strength of the spot lamp (a lot, for some reason spot lamps tend to be dimmer).
Increase the emission strength of the emission shader on Cylinder.001.
Increase the emission size of the spot lamp. This won't make it brighter, but it will help it converge faster.
Increase the exposure in Properties > Render > Color Management.